Polish national dance (7)
I believe the answer is:
mazurka
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">polish national dance</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for mazurka that I've seen before include "Polish folk dance" , "Polish dance in triple time" , "lively trip" , "Polish dance music" , "Polish national dance" .)